Application of Mechanical Probes for Evaluation of Plasma Acceleration in Ablative PPT

Abstract

In pulsed plasma thrusters (PPTs), a highly ionized plasma is created and accelerated by means of a pulsed triggered vacuum gap discharge with concurrently occurring ablation, ionization, and Lorentz-force-based acceleration of propellant. The plasma flow behavior during the PPT discharge is, therefore, highly dependent on time, space, and operation parameters. Experimental work is seen as the necessary key to further understand the processes involved and to determine future research needs. The application of mechanical probes to measure the Mach number of the plasma flow optically is discussed in this paper. Values of 1.6-3.2 were determined for a variation in time, space, and discharge voltage. An inclination of the PPT plasma flow toward the cathode was observed, which concurs with the previous research results.Index Terms-Electric space propulsion, Mach number, oblique shock, pulsed plasma thruster (PPT).

Transient buildup and dissipation of a compressed plasma shockwave in arc-discharge plasma beams

“…This is the reason that we can observe some weak shockwaves in the plasma beams of EP thrusters. It has been reported that a plasma bowshock is formed in front of a probe during the ignition of a pulsed plasma thruster (PPT) [23]. PPTs are typical EP thrusters that operate in a vacuum environment.…”

Study on the plasma generation characteristics of an induction-triggered coaxial pulsed plasma thruster

“…The PPT employed in microsatellites is usually equipped with a spark plug. A high voltage is applied to the electrodes and the spark plug is used to initiate discharge by providing a large supply of free electrons to start an avalanche in the discharge gap between the electrodes [5][6][7][8]. The operation of the spark plug needs an independent power supply, thus increasing the volume, mass and structural complexity of the thruster.…”